An introduction to TLA+ and its use in parties (2023)
TLA+ is a formal specification language used to model system behavior by defining states and transitions, ensuring desired properties are met. The article illustrates its application through a simplified example of ordering pizza at a party, using a structured process to confirm choices. This model helps verify that the final order matches participants' confirmed preferences, demonstrating how TLA+ can validate system correctness.
- ▪TLA+ is a formal specification language created by Leslie Lamport for modeling system behavior.
- ▪The pizza ordering example models a two-phase process to ensure all participants confirm their choices before finalizing the order.
- ▪The goal is to verify the property that eventually, the pizzas ordered are exactly those that were wanted and confirmed.
- ▪TLA+ uses set theory and state transitions to explore all possible system states through a model checker called TLC.
- ▪The article uses simplified syntax and examples to introduce TLA+ without covering its full complexity or related languages like PlusCal.
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| Publication time | Sat, 16 May 2026 17:24:36 +0000 |
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Jan Seeger TLA+ (standing for Temporal Logic of Actions) is a formal specification language designed by Leslie Lamport for the specification of system behavior. Roughly speaking, it allows you to model all the states that your system can have, and check certain properties on these states. TLA+ is a rather large and complex language, with another language built on top of it called PlusCal. This is why I’m not going to attempt a systematic introduction into the language, but we’ll be doing a whirlwind tour of TLA+ based on a simple example that most people are familiar with: Complicated legislative procedures on a Greek island. Just kidding, we’ll model how you’d order pizza at a party if you’re a nerd.
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